Bay,
n inter-
r star-
and
| the in-
, the
| Baffin
lere man-
er et al,
‘ears
d of
i- level
project
tribu-
, of frac-
of the
| in the
à for that
mote
; with
ings of
on sur-
inter
with a
of 9,5
S trument
in dia-
same
5 High
1:400ASA)
valuation.
nen serv-
vas used
vere oper-
‚which
rection
-100
300 km
rch 1981,
(Tab.2)
r the
As ground truth for the infrared thermometry, an ice station in the
Resolute Passage near Resolute Bay (Cornwallis Island) was used. In addition to
remote sensing, ice properties and meteorological conditions in the form of sali-
nity profiles in different ice types, temperature profiles in water, snow, ice
and air, ice growth rates, dew point profiles, wind speed and surface radiation
were recorded at this sea ice station. de
CTI TRE
| 7
^& 2 P
d ZZ ^
70°w
L/
16 7
90°w
Figure 1: North Water area
and flight path A
for remote sen- /GREENLAND ZA778°N
sing flights, La
Winter 1980/81 ine ee
C927
xi 7
Carey Isl. 40 | 700
9
76°N dd \ e
Baffin /Bay 70w
8
3 [^ 749N
1100 km__,
Ge Barrow Strait
riffith 1, 4
74? N -H 5
CORRECTIONS APPLIED TO INFRARED THERMOMETRY
EMISSIVITY: The thermal radiation measured by airborneinstrument is
affected by the emissivity of the surface, by the air layer between the ground
and the instrument and by the cloud layers above the instrument platform. The
emissivity is a function of spectral wavelength, viewing angle, surface temp-
erature and surface geometry. The radiation measurements were made in the spec-
tral band of 9.5 to 11.5 um. The radiation properties of snow,ice and water can
be assumed to be gray body in this spectral range as shown bellow:
rg
IA Jess dA ony Jf 2E dA
| 5, hc/kAT L5. hc/KAT
LA A Tully,
As Term A - Term B
(SEO ) x 100« 0.12
where c is the speed of light (2.99x10 cm/sec), T tpe surface tem -
perature in degrees Kelvin, k_Boltzmann's constant (1.3806x10 “erg/deg), h
Planck's constant (6.6252x10 “erg sec) and £ (A) the spectrally dependent emis-
sivity and £ the mean gray body emissivity for the specified spectral range. In
this study the following emissivities were used for the spectral region in
question: WATER 0.991 (Melchor,1941); ICE 0.987 (Young,1970); SNOW 0.998 (Do-
zier and Warren,1981). The cosine dependency of the emissivity of snow with a
grain size of 0.2 mm accounts for an additional apparent temperature deviation
of 0.1 C for vertical PRT-5 measurements with a 20° field-of-view (Dozier and
769
"
«X
s
f an lim in co mm OE ET EEEMEE
rue E
-:
P d
»
ti re pr e dm
LA wi | i
E
